Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00, Brno, Czech Republic.
Central European Institute of Technology, Brno University of Technology, Purkynova 123, 612 00, Brno, Czech Republic.
Sci Rep. 2021 Jul 5;11(1):13806. doi: 10.1038/s41598-021-93137-4.
In this work, we explored a new approach to a simple and sensitive fluorescence detection of thiols. The approach takes advantage of an in-situ formation of UV light-induced fluorescent nanoparticles (ZnCd/S quantum dots), while utilizing the thiol group of the analyte as a capping agent. The selectivity is ensured by the selective isolation of the thiol analyte by a polydopamine molecularly imprinted polymeric (MIP) layer. Based on this approach, a method for determination of thiols was designed. Key experimental parameters were optimized, including those of molecular imprinting and of effective model thiol molecule (L-cysteine) isolation. The relationship between the fluorescence intensity of ZnCd/S quantum dots and the concentration of L-cysteine in the range of 12-150 µg/mL was linear with a detection limit of 3.6 µg/mL. The molecularly imprinted polymer showed high absorption mass capacity (1.73 mg/g) and an excellent selectivity factor for L-cysteine compared to N-acetyl-L-cysteine and L-homocysteine of 63.56 and 87.48, respectively. The proposed method was applied for L-cysteine determination in human urine with satisfactory results. Due to a high variability of molecular imprinting technology and versatility of in-situ probe formation, methods based on this approach can be easily adopted for analysis of any thiol of interest.
在这项工作中，我们探索了一种新的方法，用于简单灵敏地荧光检测巯基。该方法利用了紫外光诱导荧光纳米粒子（ZnCd/S 量子点）的原位形成，同时利用分析物的巯基作为封端剂。选择性通过聚多巴胺分子印迹聚合物（MIP）层对巯基分析物的选择性隔离来保证。基于这种方法，设计了一种用于检测巯基的方法。优化了关键实验参数，包括分子印迹和有效模型巯基分子（L-半胱氨酸）分离的参数。ZnCd/S 量子点的荧光强度与 12-150μg/mL 范围内 L-半胱氨酸浓度之间呈线性关系，检测限为 3.6μg/mL。与 N-乙酰-L-半胱氨酸和 L-高半胱氨酸相比，印迹聚合物对 L-半胱氨酸具有高的吸附质量容量（1.73mg/g）和出色的选择性因子，分别为 63.56 和 87.48。该方法已成功应用于人尿中 L-半胱氨酸的测定，结果令人满意。由于分子印迹技术的高度可变性和原位探针形成的多功能性，基于这种方法的方法可以很容易地应用于任何感兴趣的巯基分析。
